U.S. patent application number 11/179082 was filed with the patent office on 2005-12-15 for compressible tissue anchor assemblies.
This patent application is currently assigned to USGI Medical Inc.. Invention is credited to Ewers, Richard C., Saadat, Vahid, Vong, Shirley.
Application Number | 20050277966 11/179082 |
Document ID | / |
Family ID | 46304825 |
Filed Date | 2005-12-15 |
United States Patent
Application |
20050277966 |
Kind Code |
A1 |
Ewers, Richard C. ; et
al. |
December 15, 2005 |
Compressible tissue anchor assemblies
Abstract
Apparatus & methods for optimizing anchoring force are
described herein. In securing tissue folds, over-compression of the
tissue directly underlying the anchors is avoided by utilizing
tissue anchors having expandable arms configured to minimize
contact area between the anchor and tissue. When the anchor is in
its expanded configuration, a load is applied to the anchor until
it is optimally configured to accommodate a range of deflections
while the anchor itself exerts a substantially constant force
against the tissue. Various devices, e.g., stops, spring members,
fuses, strain gauges, etc., can be used to indicate when the anchor
has been deflected to a predetermined level within the optimal
range. Moreover, other factors to affect the anchor characteristics
include, e.g., varying the number of arms or struts of the anchor,
positioning of the arms, configuration of the arms, the length of
the collars, etc.
Inventors: |
Ewers, Richard C.;
(Fullerton, CA) ; Vong, Shirley; (Aliso Viejo,
CA) ; Saadat, Vahid; (Saratoga, CA) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
USGI Medical Inc.
San Clemente
CA
|
Family ID: |
46304825 |
Appl. No.: |
11/179082 |
Filed: |
July 11, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11179082 |
Jul 11, 2005 |
|
|
|
10865243 |
Jun 9, 2004 |
|
|
|
Current U.S.
Class: |
606/153 |
Current CPC
Class: |
A61B 17/0401 20130101;
A61B 17/0469 20130101; A61B 2017/0454 20130101; A61B 17/0644
20130101; A61B 2017/0464 20130101; A61B 2017/06052 20130101; A61B
2017/00867 20130101; A61B 2017/0496 20130101; A61B 2090/037
20160201; A61B 17/0482 20130101 |
Class at
Publication: |
606/153 |
International
Class: |
A61B 017/08 |
Claims
What is claimed is:
1. An anchor assembly for securing tissue, comprising: a
compressible basket anchor having a first proximal collar, a first
distal collar, and a plurality of deformable arms each extending
between the first proximal and first distal collars; and a mesh
anchor having a second proximal collar, a second distal collar, and
a deformable mesh surface extending between the second proximal and
distal collars, wherein the basket anchor is disposed within the
mesh anchor such that the first and second proximal collars are
adjacent to one another and the first and second distal collars are
adjacent to one another.
2. The anchor assembly of claim 1 wherein the anchor assembly is
adapted to self-configure from a delivery configuration to an
expanded configuration for placement against a tissue surface.
3. The anchor assembly of claim 1 wherein the plurality of
deformable arms extend in an arcuate or spiral configuration
between the first proximal and first distal collars.
4. The anchor assembly of claim 1 wherein the compressible basket
anchor is comprised of a shape memory alloy.
5. The anchor assembly of claim 1 wherein the first proximal collar
and second proximal collar are attached to one another.
6. The anchor assembly of claim 5 wherein the first distal collar
and second distal collar are attached to one another.
7. The anchor assembly of claim 1 further comprising a length of
suture routed through the anchor assembly.
8. The anchor assembly of claim 1 wherein the basket anchor and
mesh anchor are freely movable relative to one another.
9. An anchor for securing tissue, comprising: a proximal collar; a
distal collar; and a mesh surface extending between the proximal
and distal collars, wherein the mesh surface is pre-formed to have
one or more radially-biased bulges such that compression of the
mesh surface from a delivery configuration to a securement
configuration forms a circumferential ring which inhibits passage
of the anchor through a tissue surface.
10. The anchor of claim 9 further comprising a basket anchor
disposed within the mesh surface.
11. The anchor of claim 9 further comprising a length of suture
routed through the proximal and distal collars.
12. The anchor of claim 9 wherein the mesh surface is pre-formed to
have at least two radially-biased bulges.
13. The anchor of claim 12 wherein the mesh surface is further
pre-formed to have at least one inwardly biased portion between the
two radially-biased bulges.
14. The anchor of claim 13 where the inwardly biased portion is
adapted to form a first diameter which is less than a second
diameter of the two radially-biased bulges.
15. The anchor of claim 13 further comprising a ring or band formed
at or about the inwardly biased portion for facilitating formation
of the circumferential ring.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 10/865,243 (Attorney Docket No.
21496-001800US), filed Jun. 9, 2004, which is incorporated herein
by reference in its entirety.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0002] The present invention relates to improved tissue anchors for
securement against tissue. More particularly, the present invention
relates to tissue anchors which are deployable into or against
tissue for securing portions thereof.
[0003] Morbid obesity is a serious medical condition pervasive in
the United States and other countries. Its complications include
hypertension, diabetes, coronary artery disease, stroke, congestive
heart failure, multiple orthopedic problems and pulmonary
insufficiency with markedly decreased life expectancy.
[0004] A number of surgical techniques have been developed to treat
morbid obesity, e.g., bypassing an absorptive surface of the small
intestine, or reducing the stomach size. However, many conventional
surgical procedures may present numerous life-threatening
post-operative complications, and may cause atypical diarrhea,
electrolytic imbalance, unpredictable weight loss and reflux of
nutritious chyme proximal to the site of the anastomosis.
[0005] Furthermore, the sutures or staples that are often used in
these surgical procedures typically require extensive training by
the clinician to achieve competent use, and may concentrate
significant force over a small surface area of the tissue, thereby
potentially causing the suture or staple to tear through the
tissue. Moreover, the tissue underlying the suture or staple may be
subject to becoming over-compressed to the point of becoming
subject to necrosis. Many of the surgical procedures require
regions of tissue within the body to be approximated towards one
another and reliably secured without necrosing the approximated
tissue. The gastrointestinal lumen includes four tissue layers,
wherein the mucosa layer is the inner-most tissue layer followed by
connective tissue, the muscularis layer and the serosa layer.
[0006] One problem with conventional gastrointestinal reduction
systems is that the anchors (or staples) should engage at least the
muscularis tissue layer in order to provide a proper foundation. In
other words, the mucosa and connective tissue layers typically are
not strong enough to sustain the tensile loads imposed by normal
movement of the stomach wall during ingestion and processing of
food. In particular, these layers tend to stretch elastically
rather than firmly hold the anchors (or staples) in position, and
accordingly, the more rigid muscularis and/or serosa layer should
ideally be engaged. This problem of capturing the muscularis or
serosa layers becomes particularly acute where it is desired to
place an anchor or other apparatus transesophageally rather than
intraoperatively, since care must be taken in piercing the tough
stomach wall not to inadvertently puncture adjacent tissue or
organs. Thus, an anchor is desirably non-traumatic to the
surrounding tissue. Moreover, the anchor is also desirably strong
enough to withstand the movement of the tissue.
[0007] One conventional method for securing anchors within a body
lumen to the tissue is to utilize sewing devices to suture the
stomach wall into folds. This procedure typically involves
advancing a sewing instrument through the working channel of an
endoscope and into the stomach and against the stomach wall tissue.
The contacted tissue is then typically drawn into the sewing
instrument where one or more sutures or tags are implanted to hold
the suctioned tissue in a folded condition known as a plication.
Another method involves manually creating sutures for securing the
plication.
[0008] One of the problems associated with these types of
procedures is the time and number of intubations needed to perform
the various procedures endoscopically. Another problem is the time
required to complete a plication from the surrounding tissue with
the body lumen. In the period of time that a patient is
anesthetized, procedures such as for the treatment of morbid
obesity or for GERD must be performed to completion. Accordingly,
the placement and securement of the tissue plication should ideally
be relatively quick and performed with a minimal level of
confidence.
[0009] Another problem with conventional methods involves ensuring
that the staple, knotted suture, or clip is secured tightly against
the tissue and that the newly created plication will not relax
under any slack which may be created by slipping staples, knots, or
clips. Other conventional tissue securement devices such as suture
anchors, twist ties, crimps, etc. are also often used to prevent
sutures from slipping through tissue. However, many of these types
of devices are typically large and unsuitable for low-profile
delivery through the body, e.g., transesophageally. Moreover, these
methods do not allow the surgeon to gauge the amount of force being
applied to or against the tissue by the sutures, staple, clip, etc.
Thus, over-tightening of the tissue anchor against the underlying
tissue surface may be problematic.
[0010] Moreover, when grasping or clamping onto or upon the layers
of tissue with conventional anchors, sutures, staples, clips, etc.,
many of these devices are configured to be placed only after the
tissue has been plicated and not during the actual plication
procedure.
BRIEF SUMMARY OF THE INVENTION
[0011] In securing the tissue folds or anchoring to or from these
tissue folds or plications, over-compression of the tissue directly
underlying the tissue anchors is preferably avoided.
Over-compression of the underlying tissue may occur if the anchor
compresses the tissue to such a degree that tissue necrosis or
cutting of the underlying muscularis or serosal tissue by the
anchor occurs. Accordingly, a tissue anchor is preferably
configured to maintain or secure a tissue plication yet still allow
for adequate blood flow to occur within the tissue underlying the
anchor. As such, the tissue anchor is preferably configured to
accommodate a range of deflections due to various movements of the
tissue due to, e.g., peristalsis, patient movement, weight of the
gastrointestinal organ itself, etc., while maintaining or exerting
a substantially constant force against the tissue.
[0012] A particular type of anchor which may be utilized is a
reconfigurable "basket"-type anchor generally having a number of
configurable struts or legs extending between at least two collars
or bushing members. This anchor may have a low-profile delivery
configuration and a radially expanded anchoring configuration. When
expanded, each arm of the anchor may be separated from one another
by a spacing or opening. The spacing is preferably created to
minimize the contact area between the anchor body and the
underlying tissue surface to allow for greater blood flow in the
tissue and to inhibit necrosis of the tissue.
[0013] The anchor may be made from various materials, e.g., spring
stainless steel, plastics such as polyurethane, nylon, etc., but is
preferably made from a shape memory or superelastic alloy, e.g.,
Nitinol. The anchor may thus be shaped and heat-set such that it
self-forms or automatically configures itself from the delivery
configuration to the expanded configuration upon release of a
constraining force, e.g., when the anchor is ejected from its
delivery needle or catheter. Sutures may connect a proximal anchor
to a distal anchor through the tissue fold to secure the
plication.
[0014] When the anchor has been configured into its expanded
configuration, a load or force may be applied to the anchor until
the anchor has been optimally configured to accommodate a range of
deflections while the anchor itself maintains or exerts a
substantially constant force against the tissue. Anchor deflection
may occur, e.g., when the proximal and distal collars of an anchor
have been advanced or urged towards one another such that the arms
or struts extending therebetween are at least partially deflected.
Moreover, anchor deflection may be due to various movements of the
tissue attributable to, e.g., peristalsis, patient movement, weight
of the gastrointestinal organ itself, etc.
[0015] Knowing the anchor deflection-to-exerted force
characteristics for a given anchor, one may load an anchor with a
tension or compression force such that subsequent deflections of
the underlying tissue being anchored occur within specified ranges,
such as the optimal range. For instance, an anchor may be
pre-loaded such that tissue fluctuations or movements occur within
the optimal window or range where the force exerted by the anchor
remains relatively constant over a range of deflections. This in
turn may ensure that the underlying tissue is not subject to
over-compression by the anchors.
[0016] One method for limiting the loading or pre-load force upon
an anchor may involve including a post or stop in the anchor body
which limits the proximal deflection of the distal collar and thus
prevents over-compression of the anchor against the tissue. Another
variation may utilize friction-producing regions within the anchor
delivery catheter. As the anchor is tensioned, various regions may
produce frictional forces which vary in accordance to the degree of
anchor deflection. A change in the detected frictional force may
thus be utilized to indicate that anchor has been configured within
an optimal range of deflections.
[0017] Another variation may include the use of a spring member
having a known spring constant or fuse-like member which are set to
break or fail at predetermined levels of detected force to detect
the amount of deflection an anchor has undergone. Alternatively,
measurement of material deformation via strain gauges may also be
utilized to determine the amount of deflection. The anchor
tensioning assembly may thus be configured to indicate when the
anchor has been deflected to a predetermined level, when the anchor
has been deflected within the optimal range.
[0018] Yet another variation may include configuring the proximal
collar of the anchor to prevent the passage of stop member
contained within the anchor. thus, the length of suture extending
from the stop member to the attachment point within the anchor may
be of a predetermined length such that when the stop member is
seated against the proximal collar, the suture length may compress
the anchor into a predetermined deflection level. This deflection
level may be preset to configure the anchor to any desired
configuration, as described above.
[0019] The anchors may be tensioned through various methods. One
particular method may include tensioning the anchors via an
elongate rigid or flexible shaft having a hollow lumen. A
tensioning mechanism, which is configured to receive the anchors
and grasp a tensioning suture, may be positioned near or at the
distal end of the elongate shaft. After the anchor or anchors have
been desirably tensioned, the shaft may simply be removed from the
body.
[0020] Various other factors of the tissue anchors may be modified
to affect the tensioning and loading characteristics when
deflecting the anchors. Moreover, some of the factors may also
affect the interaction of the anchor with respect to the tissue in
ensuring that the tissue is not over-compressed and that adequate
blood flow may occur within the tissue directly beneath the anchor.
Some of the factors may include, e.g., varying the number of arms
or struts of the anchor, positioning of the arms, configuration of
the arms, the length of the collars, etc.
[0021] Moreover, exposed portions of the anchor may be optionally
coated or covered with a material to protect against exposure to
foreign materials, e.g., food or other object which may be ingested
by the patient, other surgical tools, etc. Accordingly, a
biocompatible coating or covering may be placed over the entire
length of the anchor arms or only along the portions of the arms
not against the tissue. Alternatively, a mesh or skirt-like
covering may be placed over the exposed portion of the anchor or
the entire anchor itself may be covered with a distensible or
expandable covering or mesh.
[0022] In another variation, a separate mesh basket and basket
anchor may be assembled as a hybrid combination where the basket
anchor is placed within the mesh basket such that they are freely
floating with respect to one another. Alternatively, one or both
collared ends of both baskets, i.e., the basket anchor and mesh
basket, may be formed or otherwise adhered to one another. In yet
another variation, a mesh basket, alone or in combination with a
basket anchor, may be pre-formed to compress into a ringed
configuration which inhibits or resists being pulled through a
tissue region when deployed and compressed against the tissue
surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIGS. 1A and 1B show perspective views of an example of a
basket-type anchor in a delivery configuration and an expanded
configuration, respectively.
[0024] FIG. 2A shows a cross-sectional side view of one variation
for delivering a basket anchor through a needle for anchoring to a
fold of tissue.
[0025] FIG. 2B shows a cross-sectional side view of examples of how
basket anchors may be utilized in anchoring tissue plications.
[0026] FIGS. 3A and 3B show a graph of initial displacement or
deflection versus exerted force and an example of a tissue anchor
correspondingly displaced, respectively.
[0027] FIGS. 4A and 4B show the graph illustrating an optimal range
of anchor deflection where the exerted force by the anchor remains
substantially constant and the correspondingly compressed anchor,
respectively.
[0028] FIGS. 5A and 5B show the graph illustrating the rising force
for an over-compressed anchor and the correspondingly compressed
anchor, respectively.
[0029] FIGS. 6A and 6B show cross-sectional side views of an anchor
having a center post extending within the anchor for limiting the
compression of the anchor.
[0030] FIGS. 7A and 7B show cross-sectional side views of one
variation of an anchor tensioning or loading mechanism utilizing
different frictional coefficients to indicate the load placed upon
the anchor.
[0031] FIGS. 8A and 8B show the corresponding frictional force
generated utilizing the device of FIGS. 7A and 7B,
respectively.
[0032] FIG. 9 shows a partial cross-sectional view of another
variation of an anchor loading mechanism which utilizes a spring
member having a known spring constant.
[0033] FIG. 10 shows a partial cross-sectional view of another
variation of an anchor loading mechanism utilizing a strain gauge
for measuring the strain, and the resultant load, exerted upon the
anchor.
[0034] FIG. 11 shows a cross-sectional view of another variation of
an anchor loading mechanism which utilizes a stop for limiting the
anchor compression to a predetermined limit.
[0035] FIGS. 12A and 12B show partial cross-sectional views of
another variation of an anchor loading mechanism utilizing a
fuse-like device set to break or release upon reaching a
predetermined load.
[0036] FIGS. 13A and 13B show side views of various notched
fuse-members which may be utilized with the variation of FIGS. 12A
and 12B.
[0037] FIG. 14A shows a partial cross-sectional side view of a
device which may be used to apply the load upon the loading
mechanism.
[0038] FIG. 14B shows a perspective view of an alternative loading
mechanism.
[0039] FIG. 14C shows a side view of an assembly in which the
loading mechanism may be placed for applying the load upon the
anchors.
[0040] FIGS. 15A and 15B show side and edge views, respectively, of
one variation of a basket anchor in a flattened and splayed
view
[0041] FIG. 15C shows a perspective view of the anchor of FIGS. 15A
and 15B in its delivery configuration.
[0042] FIGS. 16A and 16B show side and edge views, respectively, of
another variation of a basket anchor in a flattened and splayed
view
[0043] FIG. 16C shows a perspective view of the anchor of FIGS. 16A
and 16B in its delivery configuration.
[0044] FIGS. 17A to 17J show cross-sectional end views of the
proximal (I), middle (II), and distal (III) portions of a single
anchor strut or arm showing some of the various shapes that the
anchor strut or arm may be configured.
[0045] FIGS. 18A to 18F show examples of end views of anchors
having an increasing number of struts or arms.
[0046] FIGS. 19A to 19F show examples of side views of anchors
having various strut or arm configurations.
[0047] FIGS. 20A and 20B show side views of anchors having various
configurations affected by the heights of the anchor collars.
[0048] FIG. 21A shows a perspective view of an anchor in an
expanded configuration having a protective coating or covering over
at least a portion of the struts or arms.
[0049] FIG. 21B shows a perspective view of another anchor having a
protective covering or mesh over at least a portion of the anchor
facing away from the tissue surface.
[0050] FIG. 21C shows a perspective view of another anchor having a
protective covering or mesh over the entire anchor body.
[0051] FIG. 22A shows an example of a combination hybrid basket
assembly.
[0052] FIG. 22B shows the basket assembly of FIG. 22A formed with a
second basket assembly with a length of suture routed therebetween
for tissue securement.
[0053] FIG. 23A shows the basket assembly of FIG. 22A with detail
views of either collar ends.
[0054] FIGS. 23B and 23C show the basket assembly of FIG. 23A in
use with another similar anchor in an apposed configuration in
approximating a portion of tissue into a serosa-to-serosa tissue
fold.
[0055] FIG. 24A illustrates a side view of another hybrid basket
assembly having a mesh anchor with a basket anchor contained within
having arm members or struts which are formed in a curved,
spiraled, or arcuate shape between the collars.
[0056] FIG. 24B shows the basket assembly of FIG. 24A compressed
into its disk-shaped configuration with curved or spiraled arm
members compressed into a looped, spiraled, or flower-shaped
configuration.
[0057] FIG. 25A illustrates a low-profile configuration of an
anchor having one or more radially-biased bulges pre-formed between
at least one inwardly-biased radius.
[0058] FIGS. 25B and 25C show the basket of FIG. 25A in compressed
side and top views, respectively.
[0059] FIGS. 26A and 26B show the basket anchor of FIG. 25A having
an additional ring, band, or other restraining structure integrated
or otherwise attached to the mesh.
DETAILED DESCRIPTION OF THE INVENTION
[0060] Generally, in creating and securing a plication within a
body lumen of a patient, various methods and devices may be
implemented. The anchoring and securement devices may be delivered
and positioned via an endoscopic apparatus that engages a tissue
wall of the gastrointestinal lumen, creates one or more tissue
folds, and disposes one or more of the anchors through the tissue
fold(s).
[0061] In securing the tissue folds or anchoring to or from these
tissue folds or plications, over-compression of the tissue directly
underlying the tissue anchors is preferably avoided.
Over-compression of the underlying tissue may occur if the anchor
compresses the tissue to such a degree that tissue necrosis or
cutting of the underlying muscularis or serosal tissue by the
anchor occurs. The anchor preferably exerts a force, e.g., about
0.1-0.5 lbs, sufficient to maintain or secure a tissue plication
yet still allows for adequate blood flow to occur within the tissue
underlying the anchor. Accordingly, the tissue anchor is preferably
configured to accommodate a range of deflections due to various
movements of the tissue due to, e.g., peristalsis, patient
movement, weight of the gastrointestinal organ itself, etc., while
maintaining or exerting a substantially constant force against the
tissue.
[0062] Formation of a tissue fold may be accomplished using at
least two tissue contact areas that are separated by a linear or
curvilinear distance, wherein the separation distance between the
tissue contact points affects the length and/or depth of the fold.
In operation, a tissue grabbing assembly engages or grasps the
tissue wall in its normal state (i.e., non-folded and substantially
flat), thus providing a first tissue contact area. The first tissue
contact area then is moved to a position proximal of a second
tissue contact area to form the tissue fold. The tissue anchor
assembly then may be extended across the tissue fold at the second
tissue contact area. Optionally, a third tissue contact point may
be established such that, upon formation of the tissue fold, the
second and third tissue contact areas are disposed on opposing
sides of the tissue fold, thereby providing backside stabilization
during extension of the anchor assembly across the tissue fold from
the second tissue contact area.
[0063] The first tissue contact area may be utilized to engage and
then stretch or rotate the tissue wall over the second tissue
contact area to form the tissue fold. The tissue fold may then be
articulated to a position where a portion of the tissue fold
overlies the second tissue contact area at an orientation that is
substantially normal to the tissue fold. A tissue anchor may then
be delivered across the tissue fold at or near the second tissue
contact area. One apparatus which is particularly suited to deliver
the anchoring and securement devices described herein may be seen
in further detail in co-pending U.S. patent application Ser. No.
10/735,030 filed Dec. 12, 2003, which is incorporated herein by
reference in its entirety.
[0064] Various tissue anchors may be utilized for securing the
tissue plications within the lumen. For instance, examples of
tissue anchors which may be utilized are disclosed in co-pending
U.S. patent application Ser. No. 10/612,170 filed Jul. 1, 2003,
which is incorporated herein by reference in its entirety.
Moreover, a single type of anchor may be used exclusively in an
anchor assembly; alternatively, a combination of different anchor
types may be used in an anchor assembly. One particular type of
anchor described herein is a reconfigurable "basket"-type anchor,
which may generally comprise a number of configurable struts or
legs extending between at least two collars or bushing members.
[0065] As described further below, an anchor may be adapted to
exert a substantially constant force against a tissue surface, the
anchor generally comprising a proximal collar, a distal collar, a
plurality of deformable arms each extending between the proximal
and distal collars, wherein the anchor is adapted to self-configure
from a delivery configuration to an expanded configuration for
placement against the tissue surface, and wherein the anchor is
further adapted to exert a substantially constant force against the
tissue surface over a range of deflections when the proximal and
distal collars are moved relative to one another.
[0066] One particular illustrative basket anchor is shown in the
perspective views of FIGS. 1A and 1B. FIG. 1A shows deformable
basket anchor 10 in a low-profile delivery configuration having
proximal collar or bushing 14 and distal collar or bushing 16 with
a plurality of struts or arms 12 extending between collars 14, 16.
Each arm 12 may be separated from one another by spacing or opening
20. Moreover, each arm 12 may be aligned parallel with one another
although this is not necessary. Anchor 10 may define lumen 18
through the length of anchor 10 to allow for the passage of one or
more sutures therethrough.
[0067] FIG. 1B shows a perspective view of anchor 10 of FIG. 1A in
an anchoring or expanded configuration 10'. In such a
configuration, proximal collar 14 and distal collar 16 are advanced
towards one another such that the middle section 22 of arms 12
extend radially outwardly. Anchor 10' may be made from various
materials, e.g., spring stainless steel, but is preferably made
from a shape memory or superelastic alloy, e.g., nitinol. The
anchor may thus be shaped and heat-set such that it self-forms or
automatically configures itself from the delivery configuration 10
to the expanded configuration 10' upon release of a constraining
force, e.g., when the anchor is ejected from its delivery needle or
catheter, as described further below. Alternatively, the anchor may
be configured to self-form into its expanded configuration 10' upon
the application of some activation energy to the anchor, e.g.,
electrical energy, heat from the surrounding tissue, etc.
[0068] Upon expanding, the arms 12 of anchor 10' may extend
radially outwardly such that spacing or opening 20' is defined
between adjacent arms 12. The spacing 20' is preferably created to
minimize the contact area between the anchor body and the
underlying tissue surface to allow for greater blood flow in the
tissue and to inhibit necrosis of the tissue.
[0069] When anchor 10' contacts the tissue surface, proximal collar
14 and proximal section 24 of arm 12 lay against the tissue while
distal section 26 of arm 12 extends away from the tissue surface.
Although seven arms 12 are shown in this example, the number of
arms is not intended to be limiting and may be varied, as described
in further detail below. Moreover, the configurations of proximal
24, distal 26, and middle section 22 of arms 12 may also be varied
and is also described in further detail below.
[0070] Deploying the anchors against, into, or through the tissue
may be accomplished in a number of ways. One example is shown in
FIG. 2A, which shows a cross-section of an anchor delivery system
30 in proximity to tissue fold F. Tissue fold F may comprise a
plication of tissue created using any number of tissue plication
devices. Examples of such devices which may be utilized are
described in further detail in U.S. patent application Ser. No.
10/735,030 filed Dec. 12, 2003. Tissue fold F may be disposed
within a gastrointestinal lumen, such as the stomach, where tissue
wall W may define the outer or serosal layer of the stomach. The
anchor delivery assembly may generally comprise launch tube 32 and
needle 40 slidingly disposed within the launch tube lumen. Needle
48 may generally be configured as a hollow needle having a tapered
or sharpened distal end to facilitate its travel into and/or
through the tissue.
[0071] Delivery push tube or catheter 34 may be disposed within
launch tube 32 proximally of basket anchor 10, which is shown in a
compressed delivery configuration with a relatively low profile
when disposed within needle lumen 42 of needle 40. A single basket
anchor 10 is shown disposed within needle 40 only for illustrative
purposes and is not intended to be limited by the number of basket
anchors; rather, any number of basket anchors may be disposed
within needle lumen 42 as practicable depending upon the desired
procedure and anchoring results.
[0072] Once launch tube 32 has been desirably positioned with
respect to tissue fold F, needle 40 may be urged or pushed into or
through tissue fold F via needle pushrod or member 44 from its
proximal end. As shown in FIG. 2B, basket anchor 56 has been urged
or ejected from needle 40 and is shown in its radially expanded
profile for placement against the tissue surface. In such a case, a
terminal end of suture 66 may be anchored within the distal collar
of anchor 64 and routed through tissue fold F and through, or at
least partially through, proximal anchor 56, where suture 38 may be
cinched or locked proximally of, within, or at proximal anchor 56
via any number of cinching or locking mechanisms 68. Proximal
anchor 56 is also shown in a radially expanded profile contacting
tissue fold F along tissue contact region 54. Locking or cinching
of suture 38 proximally of proximal anchor 56 enables the adequate
securement of tissue fold F.
[0073] A single suture or flexible element 38 (or multiple suture
elements) may connect proximal anchor 56 and distal anchor 64 to
one another through tissue fold F in the case of a single tissue
fold F. If additional tissue folds are plicated for securement,
distal anchor 46 may be disposed distally of at least one
additional tissue fold F' while proximal anchor 56 may be disposed
proximally of tissue fold F. As above, suture 38 may be similarly
affixed within distal anchor 46 and routed through proximal anchor
56, where suture 38 may be cinched or locked via cinching or
locking mechanism 68, as necessary. Locking mechanism 68 may be
further configured to apply a locking force upon the suture 38 such
that the anchors located upon both sides of tissue fold F (or
tissue folds F and F') may be advanced towards one another while
cinching the tissue plication(s). Suture or flexible element 38 may
comprise various materials such as monofilament, multifilament, or
any other conventional suture material, elastic or elastomeric
materials, e.g., rubber, etc.
[0074] If tissue folds F and F' are to be positioned into
apposition with one another, distal anchor 46 and proximal anchor
56 may be approximated towards one another. Proximal anchor 56 is
preferably configured to allow suture 38 to pass freely
therethrough during the anchor approximation. However, proximal
anchor 56 is also preferably configured to prevent or inhibit the
reverse translation of suture 38 through proximal anchor 56 by
enabling uni-directional travel of anchor 56 over suture 38. This
cinching feature thereby allows for the automated locking of
anchors 46, 56 relative to one another during anchor approximation.
Aspects of anchor positioning relative to tissue and various
examples of cinching or locking mechanisms may be seen in further
detail in U.S. patent application Ser. Nos. 10/840,950; 10/841,245;
10/840,951; and 10/841,411, each of which was filed May 7, 2004 and
each being incorporated herein by reference in its entirety.
[0075] The anchors, as described above, may be seen in FIG. 2B to
each have proximal collars 48, 58 and respective distal collars 50,
60 with struts or arms 52, 62 extending therebetween. As described
above, the basket anchors are preferably reconfigurable from a low
profile delivery configuration to a radially expanded deployment
configuration in which a number of struts, arms, or mesh elements
may radially extend once released from launch tube 32 or needle 40.
Materials having shape memory or superelastic characteristics or
which are biased to reconfigure when unconstrained are preferably
used, e.g., spring stainless steels, Ni--Ti alloys such as Nitinol,
etc.
[0076] The basket anchors are illustrated as having a number of
reconfigurable struts or arm members extending between a distal
collar and proximal collar; however, this is intended only to be
illustrative and suitable basket anchors are not intended to be
limited to baskets only having struts or arms, as will be described
in further detail below. Examples of suitable anchors are further
described in detail in the references which have been incorporated
by reference above as well as in U.S. patent application Ser. No.
10/612,170 filed Jul. 1, 2003, which is also incorporated herein by
reference in its entirety.
[0077] As mentioned above, the anchor preferably exerts a force
sufficient to maintain or secure a tissue plication yet still
allows for adequate blood flow to occur within the tissue
underlying the anchor. When the anchor has been configured into its
expanded configuration, a load or force may be applied to the
anchor until the anchor has been optimally configured to
accommodate a range of deflections while the anchor itself
maintains or exerts a substantially constant force against the
tissue. Anchor deflection may occur, e.g., when the proximal and
distal collars of an anchor have been advanced or urged towards one
another such that the arms or struts extending therebetween are at
least partially deflected. Moreover, anchor deflection may be due
to various movements of the tissue attributable to, e.g.,
peristalsis, patient movement, weight of the gastrointestinal organ
itself, etc.
[0078] FIGS. 3A, 4A, and 5A illustrate an example of how the
progressive deflection of an anchor may result in a substantially
constant force exerted by the anchor itself. As shown in the graph
70 of FIG. 3A, an amount of anchor deflection, x, is plotted
against the resulting force, F, exerted by the anchor. FIG. 3B
shows an illustrative profile of an exemplary anchor; proximal
collar 14, distal collar 16, and struts 12 are shown for reference.
With proximal collar 14 stationary relative to the anchor, distal
collar 16 may be urged initially at some distance, x. The anchor
may thus be configured into an initial deflected configuration 72,
as shown in FIG. 3B. The deflection may be induced via a suture or
flexible member urging the collars towards one another, e.g.,
during tissue plication formation or securement.
[0079] FIG. 3A shows the corresponding increase in force 78 over
the initial loading of the anchor through deflection, x. As the
deflection of the anchor is increased, the anchor may be configured
into a configuration 72', as shown in FIG. 4B, where the increasing
force exerted by the anchor passes an inflection point 74 and
enters an "optimal" window or range 80 in which the exerted force
remains relatively constant over a range of deflections, as shown
by the loading graph 70' in FIG. 4A. Within this range 80 of
deflections, the amount of force exerted by the anchor may be
substantially constant, i.e., relatively constant or increasing at
a rate lower than the rate of initial loading 78 or rate of "over"
loading 82 the anchor, as shown below.
[0080] At the upper portion of range 80, the force exerted by the
anchor may begin to increase relative to the deflection, as
indicated by loading curve 82 beyond inflection point 76 shown in
the loading graph 70" of FIG. 5A. FIG. 5B shows the corresponding
over-loaded anchor configuration 72" where the anchor may be seen
as having been deflected beyond the configuration shown in FIG. 4B.
The force representing the over loading of the anchor may increase
steadily until the anchor is forced into a configuration where
proximal 14 and distal 16 collars have been urged towards one
another to the point where they contact one another.
[0081] Knowing the anchor deflection-to-exerted force
characteristics for a given anchor, one may load an anchor with a
tension or compression force such that subsequent deflections of
the underlying tissue being anchored occur within specified ranges,
such as the optimal range. For instance, an anchor may be
pre-loaded such that tissue fluctuations or movements occur within
the optimal window or range where the force exerted by the anchor
remains relatively constant over a range of deflections. This in
turn may ensure that the underlying tissue is not subject to
over-compression by the anchors.
[0082] One method for limiting the loading or pre-load force upon
an anchor may involve including a post or stop 98 in the anchor
body, as shown in the anchor variation 90 of FIG. 6A, which shows a
partial cross-sectional view of the anchor. Post or stop 98 may be
integrally formed with proximal collar 94 and extend distally
between struts 92. Alternatively, post 98 may also be fabricated
separately and attached through one of a number of mechanical
methods to proximal collar 94, e.g., adhesives, threading,
interference fitted, etc. Post 98 may define a lumen to allow
suture 38 to pass through the anchor 90. The anchor 90 may be
loaded via suture 38 until the anchor 90 is configured to fall
within the optimal window or range. As the underlying tissue moves,
the anchor may be deflected accordingly; however, if the anchor is
subjected to large deflections by the tissue, post 98 may prevent
distal collar 96 of the anchor from over-compressing the anchor, as
shown in the compressed configuration 90' of FIG. 6B.
[0083] Another variation which may be utilized to limit the loading
of the anchor during anchor placement and tensioning against the
tissue is shown in the partial cross-sectional views of FIGS. 7A
and 7B. Tensioning assembly 100 may be seen proximally of anchor
proximal collar 14 contained within the delivery push tube or
catheter 102. An elongate member 104, e.g., a tubular member, may
extend through catheter 102 and define a specified region 108
having a known coefficient of friction near or at the distal end of
elongate member 104. Frictional region 108 may be an area of the
elongate member 104 having a separate material of known frictional
coefficient coated or adhered thereon. Alternatively, the
frictional region 108 may be integral with elongate member 104 and
may simply be abraded or roughened to alter the frictional
coefficient of region 108.
[0084] Suture 38 may be attached at attachment point 106 to the
distal end of elongate member 104 and may further extend into the
anchor. As elongate member 104 is slid proximally through catheter
102 to impart a tension or load upon the anchor via suture 38,
member 104 may pass through at least one or more regions which are
in intimate contact around member 104. The regions in contact with
member 104 may comprise at least a first frictional area 110 having
a known first frictional coefficient. As elongate member 104 is
withdrawn proximally in the direction of travel 118, frictional
region 108 may slide against first frictional area 110 and generate
a first frictional force I, as indicated by plot 120 on the graph
of FIG. 8A. The generated first frictional force I may be detected
through any number of various devices and may be used to indicate
to the operator that anchor is being loaded.
[0085] As elongate member 104 is withdrawn further proximally,
frictional region 108 may be withdrawn proximally of first
frictional area 110 and against second frictional area 112, which
may also have a known second frictional coefficient different from
the first frictional coefficient of the first frictional area 110,
as shown in FIG. 7B. A length of first frictional area 110 may
accordingly be configured to correspond to the length of suture
needed to load the anchor into its optimal configuration. As
elongate member 104 slides against second frictional area 112, a
second frictional force II may be generated which may be less than
the first frictional force. FIG. 8B shows the drop in the generated
frictional force as indicated by plot 122. This change in the
detected force may thus be utilized to indicate to the operator
that anchor has been configured within an optimal range of
deflections. Once the anchor has been optimally configured, the
suture may be secured relative to the anchor using any number of
the cinching and/or locking methods as described in U.S. patent
application Ser. Nos. 10/840,950; 10/841,245; 10/840,951; and
10/841,411, each being incorporated by reference above.
[0086] To prevent elongate member 104 from being over-withdrawn
proximally and from over-compressing the anchor, protrusions 114
may project from elongate member 104 and corresponding stops 116
may project from within catheter 102. Protrusions 114 and the
corresponding stops 116 may accordingly be configured to prevent
the further withdrawal of elongate member 104 from catheter 102.
Moreover, although first 110 and second 112 frictional areas are
shown in this example, a single frictional area or additional areas
may be utilized, each having a different coefficient of friction.
Furthermore, first 110 and second 112 frictional areas may be
fabricated from different materials or they may be made from the
same or similar material as catheter 102 and simply coated or
covered with the various materials. For instance, first frictional
area 110 may be fabricated from a material such as PEBAX.RTM.,
while second frictional area 112 may be fabricated from a material
such as HDPE. Alternatively, rather than utilizing a coating or
covering, first 110 and second 112 frictional areas may be textured
or abraded to create surfaces having differing frictional
coefficients. The types of materials utilized or the types of
surface textures created or even the number of different frictional
areas are not intended to be limiting but are merely presented as
possible variations. So long as a detectable change in the
generated frictional force between elongate member 104 and the
surrounding frictional region is created, any number of materials
or regions may be utilized.
[0087] FIG. 9 shows another anchor tensioning variation in assembly
130. As shown, the tensioning assembly may be contained within
delivery push tube or catheter 132. An elongate pull member 134,
which may be manipulated via its proximal end by the user, may be
connected to a tensioning block or member 136 via spring member
138. Pull member 134 and tensioning block or member 136 may
generally be formed from a variety of biocompatible metals, e.g.,
stainless steel, Nitinol, etc., or plastics provided that the
material is rigid relative to spring member 138 and suture 140 and
will not affect the measurement of the linear deformation of spring
member 138. Spring member 138 may generally comprise a linear
spring element having a known spring constant. Suture 140 may be
attached to a distal end of block 136 and further routed into or
through distally located the tissue anchor.
[0088] During use in loading the tissue anchor, pull member 134 may
be withdrawn proximally by its proximal end. As it is withdrawn,
the force required to withdraw member 134 may be measured. With the
spring constant and the measured force, the amount of linear
deflection may be calculated to determine the amount of deflection
the anchor has undergone. Alternatively, suture 140 may be marked
uniformly at known distances with markings or gradations 142. As
the pull member 134 is withdrawn, the length of suture 140
withdrawn into catheter 132 may be measured visually using, e.g., a
video endoscope, by counting the number of gradations 142 passing
into catheter 132. Knowing the linear distance and the spring
constant, the anchor deflection may be calculated. Thus,
measurement of either the force required to withdraw member 134 or
the linear distance traveled by suture 140 may be utilized to
determine the anchor deflection. With the known deflection, the
assembly may be configured to indicate when the anchor has been
deflected to a predetermined level, e.g., when the anchor has been
deflected within the optimal range.
[0089] Another alternative of an anchor tensioning assembly is
shown in the partial cross-sectional view of FIG. 10. Assembly 150
may generally comprise an elongate pull member 152 connected to
tensioning block or member 154. Pull member 152 and tensioning
block 154 may be fabricated from the same or similar materials as
described above. A third element 156 having a known length which is
less rigid than pull member 152 or tensioning block 154 may connect
the two. This element 156 may have strain gauge 158 attached
thereto for measuring the strain of the element 156 as pull member
152 is withdrawn proximally. The signals detected from the strain
gauge 158 may be transmitted via wires 160 to a processor and/or
display 162 located externally of the patient to record and process
the strain information. With the known original length of element
156 and the measured strain, the length of linear deflection of the
attached anchor may be calculated. With this information, the
anchor deflection may be determined and the assembly 150 may be
configured to indicate when the anchor has been deflected to a
predetermined level to ensure optimal loading of the anchor.
[0090] Yet another alternative is shown in the partial
cross-sectional view of FIG. 11. In this variation, assembly 170
may simply comprise an anchor having a stepped proximal collar 172
to define a step or detent 174 which prevents the passage of stop
member 176 contained within the anchor. The length of suture 38
extending from stop member 176 to the attachment point within the
anchor may be of a predetermined length such that when stop member
176 is seated against proximal collar 172, the suture length may
compress the anchor into a predetermined deflection level. This
deflection level may be preset to configure the anchor to any
desired configuration, as described above.
[0091] Yet another variation is shown in the partial
cross-sectional views of FIGS. 12A and 12B. Assembly 180 may
generally comprise elongate pull member 152 and tensioning block or
member 154, as above. However, a fuse material 182, i.e., a length
of material having a preset or known failure or break strength, may
be used to join pull member 152 and tensioning block 154. This fuse
182 may generally comprise a variety of materials, e.g., silk,
stainless steel, etc., provided that the failure strength of fuse
182 is less than the force necessary for causing necrosis of the
tissue to be anchored. For instance, a fuse 182 may be configured
to break at a pressure of, e.g., 2 psi.
[0092] In operation, as elongate pull member 152 is withdrawn
proximally, tensioning block 154 may be withdrawn as it is pulled
by fuse 182. As the anchor becomes compressed and the force on fuse
182 increases, once the force reaches the pre-set limit, the fuse
182 may break, as shown in FIG. 12B, thereby preventing further
compression of the anchor and limiting the force applied onto the
tissue.
[0093] Fuse 182 may be comprised from various materials.
Optionally, the fuse may be altered to modify its break strength,
e.g., by including multiple notches 192, 194, as seen in fuse
variation 190 of FIG. 13A to create a necked-down region.
Alternatively, a single notch 198 may be utilized, as seen in fuse
variation 196. The notches may be defined on the fuse to alter the
break strength or to ensure the breakage or failure of the
fuse.
[0094] When tensioning the anchors using any of the devices or
methods described herein, various mechanisms may be used to apply
the tensioning force on the suture. One mechanism is shown in the
partial cross-sectional view of FIG. 14A, which shows a tensioning
assembly 200 positioned within catheter 132. The assembly may
generally comprise tensioning mechanism 202, which may have an
anchor interface member 206 and a tensioning interface member 208
configured to slide relative to one another within catheter 132.
Anchor interface member 206 may define anchor collar channel 204
configured to receive and temporarily hold the proximal collar 14
of an anchor to be loaded.
[0095] Tensioning interface member 208 may be configured to slide
relative to anchor interface member 206 via a slidable connection
210. Tensioning member 208 may also comprise suture coupler 212 and
hook 214 for holding terminal end 216 of suture 38 during a
tensioning procedure. Tensioning member 208 and anchor member 206
may be urged towards one another via some biased member, e.g.,
spring member 218, having a known spring constant. In use, when a
tissue anchor is ready to be loaded, the proximal collar 14 may be
held within anchor collar channel 204 and with terminal end 216 of
suture 38 retained by hook 214, tensioning member 208 may be
withdrawn proximally relative to anchor member 206 until the
desired tensioning level is reached. Other variations utilizing,
e.g., a strain gauge, for measuring the tension applied or
utilizing, e.g, graspers, rather than a hook may be utilized to
desirably tension the tissue anchors.
[0096] FIG. 14B shows a perspective view of an alternative
tensioning assembly 201 which may be used to apply the load upon
the anchor. This assembly 201 may be utilized in conjunction with
any of the tension measuring apparatus described herein. As shown,
anchor 10' may be positioned at the distal end of base 205 with
suture 38 extending proximally while being tensioned via suture
coupler 212, as in assembly 200 described above. Graspers 203,
which may be articulated to open or close, may be used to hold
suture terminal end 216 while tensioning anchor 10'. Base 205 may
be configured to extend longitudinally, as above, or suture coupler
212 may be configured to slide proximally to tension the anchor
10'.
[0097] FIG. 14C shows a device which may be used by the surgeon or
operator outside a patient body to tension the anchors positioned
within the body. Generally, the handle assembly may comprise handle
211 and a hollow elongate shaft 215 extending from the handle 211.
Shaft 215 may function much like a laparoscopic shaft if shaft 215
is rigid; alternatively, shaft 215 may be configured to be flexible
for advancement within or through an endoscope or other working
lumen, if so desired. A tensioning assembly, as described above,
may be positioned within the lumen of shaft 215 near or at the
distal end of shaft 215 and the control mechanisms, e.g., suture
coupler 212, may be actuatable from handle 211. In one variation,
control wheel or ratchet control 213, which may be located on
handle 211, may be rotated in the direction of arrow 217 to actuate
base 205 or suture coupler 212 in a proximal direction, as
indicated by arrow 219. Tensioning suture 38 with ratchet control
217 may draw anchors 207, 209 towards one another to secure tissue
fold F while also applying an appropriate load upon anchors 207,
209.
[0098] Various other factors of the tissue anchors may be modified
to affect the tensioning and loading characteristics when
deflecting the anchors. Moreover, some of the factors may also
affect the interaction of the anchor with respect to the tissue in
ensuring that the tissue is not over-compressed and that adequate
blood flow may occur within the tissue directly beneath the
anchor.
[0099] One factor may include varying the number of arms or struts
of the anchor. For instance, the anchor may be configured to have,
e.g., seven struts or arms 12 which deflect about the proximal 14
and distal 16 collars, as shown in the flattened view of one anchor
variation 220 in FIG. 15A. FIG. 15B shows a side view of the
flattened anchor 220 while FIG. 15C shows a perspective view of the
anchor 220 in an unexpanded delivery configuration.
[0100] FIG. 16A shows another variation of anchor 230 in a
flattened view with struts or arms 232 extending between proximal
collar 236 and distal collar 238. In this variation, five arms 232
may be utilized to increase the spacing 234 defined between
adjacent arms 232. The increased spacing 234 may be utilized to
ensure the blood flow in the tissue beneath the tissue. FIG. 16B
shows a side view of the flattened anchor 230 and FIG. 16C shows a
perspective view of anchor 230 in its unexpanded delivery
configuration. Other variations are discussed below.
[0101] Aside from varying the number of struts or arms, the
configuration of the arms themselves may be varied. As seen in FIG.
16A, cross-sections of an individual arm 232 may be viewed for
discussion purposes at three sections, proximal I, middle II, and
distal III portions of the arm 232. FIGS. 17A to 17J show examples
of possible variations for cross-sectional areas of an arm at each
section, proximal I, middle II, and distal III. These figures are
not intended to be limiting but are merely intended as examples of
possible arm configurations.
[0102] FIG. 17A shows an arm configuration where sections I and III
may be square in shape with the middle section II rectangular.
[0103] FIG. 17B shows an arm configuration where sections I and III
may be rectangular in shape with the middle section II square. FIG.
17C shows an arm configuration where sections I and III may be
rectangular in shape in a transverse direction with the middle
section II square.
[0104] FIG. 17D shows an arm configuration where sections I and III
may be square in shape with the middle section II rectangular in a
traverse direction.
[0105] FIG. 17E shows an arm configuration where all sections I,
II, and III may be square in shape.
[0106] FIG. 17F shows an arm configuration where all sections I,
II, and III may be rectangular in shape.
[0107] FIG. 17G shows an arm configuration where sections I and III
may be circular in shape with the middle section II
rectangular.
[0108] FIG. 17H shows an arm configuration where sections I and III
may be elliptical in shape with the middle section II circular.
[0109] FIG. 17I shows an arm configuration where sections I and III
may be circular in shape with the middle section II elliptical.
[0110] FIG. 17J shows an arm configuration where all sections I,
II, and III maybe circular in shape.
[0111] As mentioned above, varying the number of struts or arms may
be utilized to vary not only the contact area with respect to the
underlying tissue, but to also affect the optimal loading
characteristics of the anchor. Aside from the number of arms, the
positioning of the arms may also be utilized. For example, FIGS.
18A to 18F show end views of anchor variations having a number of
varying arms and arm positions. Again, these figures are not
intended to be limiting but are merely intended as examples.
[0112] FIG. 18A shows the end view of an anchor 240 having 3 arms
uniformly spaced apart.
[0113] FIG. 18B shows the end view of an anchor 242 having 4 arms
uniformly spaced apart.
[0114] FIG. 18C shows the end view of an anchor 244 having 5 arms
uniformly spaced apart.
[0115] FIG. 18D shows the end view of an anchor 246 having 6 arms
uniformly spaced apart.
[0116] FIG. 18E shows the end view of an anchor 248 having 7 arms
uniformly spaced apart.
[0117] FIG. 18F shows the end view of an anchor 250 having 9 arms
uniformly spaced apart.
[0118] Any number of arms may be utilized as practicable and
although the arms in the above examples are uniformly spaced apart
from one another, the spacing between the arms may be varied
irregularly or arbitrarily provided that the spacing between the
arms enable adequate blood flow in the underlying tissue.
[0119] Not only can the number of arms and spacing between the arms
be varied, but also the arm configurations themselves. For
instance, the arms may be pre-formed into various shapes depending
upon the desired effects on the anchor loading characteristics. As
above, these figures are not intended to be limiting but are merely
intended as examples.
[0120] FIG. 19A shows an illustrative side view of anchor 260
having curved arms.
[0121] FIG. 19B shows an illustrative side view of anchor 262
having circularly-shaped arms.
[0122] FIG. 19C shows an illustrative side view of anchor 264
having elliptically-shaped arms.
[0123] FIG. 19D shows an illustrative side view of anchor 266
having bow-shaped arms.
[0124] FIG. 19E shows an illustrative side view of anchor 268
having arms shaped into a figure-eight manner.
[0125] FIG. 19F shows an illustrative side view of anchor 270
having minimally-radiused arms.
[0126] Aside from the arm shapes, the length of the collars may be
varied as well. FIG. 20A shows anchor variation 280 having extended
anchor collars 282, which may act to reduce the radius of the arms.
FIG. 20B shows anchor variation 284 having reduced collars 286,
which may act to increase the radius of the arms. As above, these
figures are not intended to be limiting but are merely intended as
examples.
[0127] When the anchors are deployed into or against the tissue, at
least one portion of the anchor arms are generally against the
tissue surface while another portion of the arms are exposed within
the lumen. The exposed portions of the anchor may be optionally
coated or covered with a material to protect against exposure to
foreign materials, e.g., food or other object which may be ingested
by the patient, other surgical tools, etc. Accordingly, as shown in
the perspective view of anchor variation 290 in FIG. 21A,
biocompatible coating or covering 292 may be placed over the entire
length of the anchor arms 12 or only along the portions of the arms
12 not against the tissue. The coating or covering 292 may be
comprised from various materials, e.g., elastomers, plastics,
etc.
[0128] Alternatively, a mesh or skirt-like covering 298 may be
placed over the exposed portion of the anchor 294, as shown in FIG.
21B, which is attached to the anchor via attachment points 298
along each of some of the arms 12. Yet another alternative may be
seen in anchor variation 300 in FIG. 21C in which the entire anchor
itself may be covered with a distensible or expandable covering or
mesh.
[0129] In yet another variation shown in FIG. 22A, a combination
hybrid basket assembly 310 may generally comprise basket anchor 10,
as previously described, which may be placed entirely within a
basket anchor 312 comprised primarily of a mesh or distensible
material, e.g., PTFE, PET, etc. Each anchor, i.e., basket anchor 10
and mesh anchor 312, may each be formed individually and basket
anchor 10 may be positioned through mesh basket opening 320 such
that basket anchor 10 is entirely enveloped by mesh 318 within mesh
basket 312. Mesh basket 312 may be comprised generally of a mesh
318 having proximal 314 and distal 316 collars, as shown. Moreover,
mesh 318 may be pre-formed to expand from a low profile
configuration for delivery into an expanded configuration for
deployment.
[0130] When deployed for tissue securement, one or more hybrid
basket assemblies, e.g., first basket assembly 310A and second
basket assembly 310B as shown in FIG. 22B, may be interconnected
via suture 38 such that suture 38 passes freely through one or both
basket assemblies 310A, 310B.
[0131] Generally, basket anchor 10 may freely float within mesh
basket 312 such that the proximal 14 and distal 16 collars of
basket anchor 10 are freely moveable with respect to proximal 314
and distal 316 collars of mesh basket 312, as shown and described
above. Alternatively, one or both ends of the anchor collars may be
fused or formed to one another. For example, as shown in FIG. 23A,
basket assembly 310 may be seen with detail views of either collar
ends. In this example, distal collar 16 of basket anchor 10 may
freely move, as shown by arrow 332, with respect to distal collar
316 of mesh basket 312 through mesh basket opening 320 at
free-anchor end 336. Distal collar 316 may also freely move, as
shown by arrows 330. The proximal collar 14 of basket anchor 10, on
the other hand, may be fused, formed, welded, adhered, or otherwise
attached to proximal collar 314 of mesh basket 312 at fused-anchor
end 334 such that relative movement between the collars 14, 314 is
prohibited or restrained.
[0132] Thus, when proximal collars 14, 314 at fused-anchor end 334
are placed against a tissue surface to be secured, distal collars
16, 316 at free-anchor end 336 may freely translate with respect to
one another such that anchor assembly 310 may be fully cinched or
compressed freely without any mismatched compression occurring
between basket anchor 10 and mesh anchor 312. Alternatively, distal
collars 16, 316 may also be fused or attached to one another such
that movement of either collar ends are fully constrained with
respect to each anchor. In such an alternative, the compression
rate of basket anchor 10 is preferably matched with that of mesh
anchor 312.
[0133] An example of use for the fused hybrid anchors is shown in
FIG. 23B. A distal hybrid anchor 310 having a basket anchor
enclosed within mesh 318 may be deployed on a first side of a
tissue region to be plicated, e.g., into a tissue fold F, as
described above. The proximal collars 14, 314 of the hybrid anchor
assembly 310 may be deployed such that fused-anchor anchor end 334
rests against or abuts the surface of the tissue. With suture 38
passing through distal hybrid anchor 310 and through the
dual-layers of tissue fold F, a proximal hybrid anchor 310',
likewise having a basket anchor enclosed within mesh 318', may be
deployed on a proximal side of the tissue fold F such that its
proximal collars of fused-anchor end 334' rests against or abuts
the surface of the tissue, also as described above. Suture 38 may
also pass from the tissue fold F and through the proximal hybrid
anchor 310'.
[0134] As the hybrid anchors 310, 310' are approximated towards one
another by tensioning suture 38, the tissue is formed into a
serosa-to-serosa contacting tissue fold F, as shown in FIG. 23C. As
the hybrid anchors 310, 310' are further cinched towards one
another, the free-floating collars 16, 16' of their respective
free-anchor ends 336, 336' may freely move while the respective
fused-anchor ends 334, 334' may each lie against the surface of
tissue fold F. Thus, having the translating free-anchor ends 336,
336' of the apposed basket anchors positioned away from the
plicated tissue while having the fused-anchor ends 334, 334' placed
against the plicated tissue may ensure smooth anchor compression
and cinching of the tissue.
[0135] In another variation, FIG. 24A illustrates a side view of
another hybrid basket assembly 340 having a mesh anchor 312 with a
basket anchor contained within having arm members or struts 342
which are formed in a curved, spiraled, or arcuate shape between
collars 14, 16. When compressed for securing tissue, mesh anchor
312 may compress into its disk-shaped configuration, but curved or
spiraled arm members 342 may compress into a looped, spiraled, or
flower-shaped configuration, as shown in the top compressed view of
FIG. 24B. Such a spiraled configuration may allow for compression
of the basket anchor within the mesh anchor 312 while retaining a
smooth or atraumatic outer diameter with respect to an inner
surface of the mesh 318 when compressed.
[0136] In yet another variation, compressible anchor 350 may be
comprised generally of a mesh 356, as described above, which is
pre-formed to compress into a double-disk configuration. FIG. 25A
shows a low-profile configuration of the anchor 350 having one or
more radially-biased bulges 352 pre-formed between at least one
inwardly-biased radius 354. When compressed, as shown in FIG. 25B,
radially-biased bulges 352 may each flatten radially into a
disk-shaped configuration adjacently formed with respect to one
another while inwardly-biased radius 354 is biased to flatten in an
opposite direction. As shown in the top compressed view in FIG.
25C, bulges 352 may essentially form hardened circumferential rings
of flattened mesh 356 which further inhibit or prevent the tissue
anchors from being pulled through the secured tissue. Although
compressible anchor 350 is shown as a mesh basket, a basket anchor
may also be placed therewithin, if so desired.
[0137] In a further variation, an additional ring, band, or other
structure may be integrated with the anchor of FIGS. 25A to 25C to
facilitate the formation of the circumferential rings when the
anchor is flattened. For instance, FIGS. 26A and 26B show
compressible anchor 360 having the ring, band, or other retaining
structure 362 formed at or along inwardly-biased radius 354. This
structure 362 may be integrally formed with mesh 356 by an adhesive
or other mechanism. Structure 362 may be formed into, e.g., a
circular or elliptical ring or band, made of any number of
non-distensible or partially distensible polymeric or elastomeric
materials, e.g., PTFE, silicon, urethane, etc., or any number of
other metals or alloys, e.g., Nitinol, stainless steel, etc. When
the anchor 360 expands from its low-profile configuration, as shown
in FIG. 26A, the structure 362 may retain the portion of mesh 356
around radius 354 such that when the anchor 360 is flattened
against the tissue surface, the bulges 352 may more easily flatten
into their expanded configurations about radius 354, as shown in
FIG. 26B.
[0138] Although a number of illustrative variations are described
above, it will be apparent to those skilled in the art that various
changes and modifications may be made thereto without departing
from the scope of the invention. Any of the modifications to an
anchor, e.g., number of arms, arm configuration, cross-sectional
variations, anchor collar length, coatings or coverings over the
anchor, etc., may be done in a variety of combinations with one
another. For instance, depending upon the desired loading
characteristics, an anchor may be made having a number of arms with
various cross-sectional areas along one or more of the arm lengths
and may additionally have one or both collars varied in length.
[0139] Any of the combinations or modifications is intended to be
within the scope of this invention. Moreover, although
configurations may be shown with various types of anchors, it is
intended that the various configurations be utilized in various
combinations as practicable. It is intended in the appended claims
to cover all such changes and modifications that fall within the
true spirit and scope of the invention.
* * * * *